Waiman Long 3fb906e7fa cgroup/cpuset: Don't filter offline CPUs in cpuset_cpus_allowed() for top cpuset tasks ... Since commit 8f9ea86fdf ("sched: Always preserve the user requested cpumask"), relax_compatible_cpus_allowed_ptr() is calling __sched_setaffinity() unconditionally. This helps to expose a bug in the current cpuset hotplug code where the cpumasks of the tasks in the top cpuset are not updated at all when some CPUs become online or offline. It is likely caused by the fact that some of the tasks in the top cpuset, like percpu kthreads, cannot have their cpu affinity changed. One way to reproduce this as suggested by Peter is: - boot machine - offline all CPUs except one - taskset -p ffffffff $$ - online all CPUs Fix this by allowing cpuset_cpus_allowed() to return a wider mask that includes offline CPUs for those tasks that are in the top cpuset. For tasks not in the top cpuset, the old rule applies and only online CPUs will be returned in the mask since hotplug events will update their cpumasks accordingly. Fixes: 8f9ea86fdf ("sched: Always preserve the user requested cpumask") Reported-by: Will Deacon <will@kernel.org> Originally-from: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Will Deacon <will@kernel.org> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>		2023-02-06 10:15:08 -10:00
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cgroup-internal.h	memcg: fix possible use-after-free in memcg_write_event_control()	2022-12-09 18:41:17 -08:00
cgroup-v1.c	cgroup: Use cgroup_attach_{lock,unlock}() from cgroup_attach_task_all()	2022-08-26 11:14:34 -10:00
cgroup.c	Networking changes for 6.2.	2022-12-13 15:47:48 -08:00
cpuset.c	cgroup/cpuset: Don't filter offline CPUs in cpuset_cpus_allowed() for top cpuset tasks	2023-02-06 10:15:08 -10:00
debug.c	kernel: cgroup: fix misuse of %x	2019-05-06 08:47:48 -07:00
freezer.c	cgroup: cleanup comments	2022-03-13 19:19:27 -10:00
legacy_freezer.c	freezer,sched: Rewrite core freezer logic	2022-09-07 21:53:50 +02:00
Makefile	cgroup: Add misc cgroup controller	2021-04-04 13:34:46 -04:00
misc.c	misc_cgroup: remove error log to avoid log flood	2021-09-20 07:35:38 -10:00
namespace.c	memcg: enable accounting for new namesapces and struct nsproxy	2021-09-03 09:58:12 -07:00
pids.c	cgroup: add pids.peak interface for pids controller	2022-09-04 09:26:51 -10:00
rdma.c	cgroup: fix spelling mistakes	2021-05-24 12:45:26 -04:00
rstat.c	cgroup: bpf: enable bpf programs to integrate with rstat	2022-08-25 11:35:37 -07:00